Patents by Inventor Tomoko Ohtsuki
Tomoko Ohtsuki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7277220Abstract: A laser apparatus including a laser generating portion that generates pulse light having a single wavelength within a range from an infrared band to a visible band. An optical amplifier is optically connected to the laser generating portion, and includes a plurality of fiber optical amplifiers to amplify the pulse light a plurality of times. A wavelength converting portion is optically connected to the optical amplifier, and includes cylindrical lenses and a plurality of non-linear optical crystals to wavelength-convert the amplified pulse light into ultraviolet light. The amplified pulse light is incident on the cylindrical lenses through one of the plurality of non-linear optical crystals and is incident on a different one of the plurality of non-linear optical crystals from the one non-linear optical crystal through the cylindrical lenses.Type: GrantFiled: September 13, 2006Date of Patent: October 2, 2007Assignee: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Patent number: 7212275Abstract: A laser apparatus that includes a laser light generation section, an optical amplification section, a wavelength conversion section and a suppressing section is provided. The laser light generation section includes a single wavelength oscillatory laser and generates pulsed light having a single wavelength within a wavelength range ranging from about 1.51 to 1.59 ?m. The optical amplification section includes an optical fiber amplifier and is optically connected to the laser light generation section to amplify the pulsed light. The wavelength conversion section includes a nonlinear optical crystal and is optically connected to the optical amplification section to perform wavelength conversion of the amplified pulsed light into ultraviolet light. The suppressing section suppresses expansion of a wavelength width of light originated in a nonlinear effect of an optical element between the single wavelength oscillatory laser and the wavelength conversion section.Type: GrantFiled: April 22, 2005Date of Patent: May 1, 2007Assignee: Nikon CorporationInventor: Tomoko Ohtsuki
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Publication number: 20070008609Abstract: An ultraviolet laser apparatus according to the present invention comprises a laser generating portion having a single-wavelength oscillating laser for generating laser light having a single wavelength falling within a wavelength range from an infrared band to a visible band, an optical amplifier having a fiber optical amplifier for amplifying the laser light generated by the laser generating portion, and a wavelength converting portion for wavelength-converting the amplified laser light into ultraviolet light by using a non-linear optical crystal, whereby ultraviolet light having a single wavelength is generated.Type: ApplicationFiled: September 13, 2006Publication date: January 11, 2007Applicant: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Patent number: 7136402Abstract: A laser device which can be used as a light source for an exposure device, can be downsized, and is easy to maintain. A laser beam (LB6) emitted from a DFB (Distributed feedback) semiconductor laser, for example, and amplified by an optical fiber amplifier is passed through non-linear optical crystals (502, 503, 504) to be sequentially doubled in frequency to thereby generate an ultraviolet-region laser beam (LB5) consisting of an octuple wave. A GdYCOB, that is, GdxY1?xCa4O(BO3)3 crystal (0?×?1) is used for the non-linear optical crystal (503) for a double wave-to-quadruple wave conversion, and a KAB, that is, K2Al2B4O7 crystal for the non-linear optical crystal (504) for a quadruple wave-to-octuple wave conversion. The non-linear optical crystals (502-504) are all fine-tuned in phase match angle by temperature controllers (521-523) respectively.Type: GrantFiled: September 8, 2000Date of Patent: November 14, 2006Assignee: Nikon CorporationInventor: Tomoko Ohtsuki
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Patent number: 7126745Abstract: A method of irradiating ultraviolet light onto an object. The method includes generating pulse light having a single wavelength within a range from 1.51 ?m to 1.59 ?m from a laser generating portion, amplifying the pulse light plural times with an optical amplifier that includes a plurality of fiber optical amplifiers, wavelength-converting the amplified pulse light into ultraviolet light with a wavelength converting portion that includes a plurality of non-linear optical crystals, and irradiating the ultraviolet light onto the object through an optical system.Type: GrantFiled: December 22, 2005Date of Patent: October 24, 2006Assignee: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Patent number: 7098992Abstract: The light source unit includes a single wavelength oscillation light source, a light generating portion which has an optical modulator converting and emitting light from the light source into a pulse light, a light amplifying portion made up of an optical fiber group in which each fiber has a fiber amplifier to amplify the pulse light from the optical modulator, and a light amount controller. The light amount controller performs a step-by-step light amount control by individually turning on/off the light output of each fiber making up the optical fiber group, and a light amount control of controlling at least either of the frequency or the peak power of the emitted pulse light of the optical modulator.Type: GrantFiled: July 15, 2003Date of Patent: August 29, 2006Assignee: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa, Niichi Atsumi, Masaaki Doi
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Publication number: 20060098269Abstract: An ultraviolet laser apparatus according to the present invention comprises a laser generating portion having a single-wavelength oscillating laser for generating laser light having a single wavelength falling within a wavelength range from an infrared band to a visible band, an optical amplifier having a fiber optical amplifier for amplifying the laser light generated by the laser generating portion, and a wavelength converting portion for wavelength-converting the amplified laser light into ultraviolet light by using a non-linear optical crystal, whereby ultraviolet light having a single wavelength is generated.Type: ApplicationFiled: December 22, 2005Publication date: May 11, 2006Applicant: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Patent number: 7023610Abstract: An ultraviolet laser apparatus having a single-wavelength oscillating laser generating laser light between an infrared band and a visible band, an optical amplifier for amplifying the laser light, and a wavelength converting portion converting the amplified laser light into ultraviolet light using a non-linear optical crystal. An exposure apparatus transfers a pattern image of a mask onto a substrate and includes a light source having a laser apparatus emitting laser light having a single wavelength, a first fiber optical amplifier for amplifying the laser light, a light dividing device for dividing or branching the amplified laser light into plural lights, and second fiber optical amplifiers for amplifying the plural divided or branched lights, respectively, and a transmission optical system for transmitting the laser light emitted from the light source to the exposure apparatus.Type: GrantFiled: February 19, 2003Date of Patent: April 4, 2006Assignee: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Publication number: 20060028712Abstract: A system, method and computer program product for determining excited state absorption (ESA) dependent parameters (gain and noise figure) of an EDF and an EDFA corresponding to a determined average inversion value of an EDF. Also, a system, method and computer program product for using an EDFA model that incorporates ESA parameters to in calculating an EDFA gain and noise figure to design laser systems with high accuracy.Type: ApplicationFiled: May 9, 2005Publication date: February 9, 2006Applicants: FURUKAWA AMERICA, INC, OFS FITEL, LLCInventors: Tomoko Ohtsuki, Jutarou Miura, Masaru Fukushima, Baishi Wang
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Patent number: 6947123Abstract: An exposure apparatus has a light source comprising a laser device that is small and easy to maintain. The laser device comprises a laser oscillator for generating a single-wavelength laser beam (LB3) within a wavelength range including infrared and visible regions; an optical amplifier (18) for amplifying a laser beam (LB3); and a wavelength converter for converting the amplified laser beam into ultraviolet light using a nonlinear optical crystal. The optical amplifier (18) includes a plurality of stages of optical fiber amplifiers (22, 25) for sequential amplification of the laser beam (LB3), and a narrow-band filter (24A) and an isolator (IS3) arranged between optical fiber amplifiers.Type: GrantFiled: September 8, 2000Date of Patent: September 20, 2005Assignee: Nikon CorporationInventor: Tomoko Ohtsuki
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Publication number: 20050185683Abstract: A laser apparatus that includes a laser light generation section, an optical amplification section, a wavelength conversion section and a suppressing section is provided. The laser light generation section includes a single wavelength oscillatory laser and generates pulsed light having a single wavelength within a wavelength range ranging from about 1.51 to 1.59 ?m. The optical amplification section includes an optical fiber amplifier and is optically connected to the laser light generation section to amplify the pulsed light. The wavelength conversion section includes a nonlinear optical crystal and is optically connected to the optical amplification section to perform wavelength conversion of the amplified pulsed light into ultraviolet light. The suppressing section suppresses expansion of a wavelength width of light originated in a nonlinear effect of an optical element between the single wavelength oscillatory laser and the wavelength conversion section.Type: ApplicationFiled: April 22, 2005Publication date: August 25, 2005Applicant: NIKON CORPORATIONInventor: Tomoko Ohtsuki
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Patent number: 6901090Abstract: An exposure apparatus has a laser device that is small, easy to maintain, and capable of producing an output that is unlikely to be affected by optical surges occurring in the beginning of operation. A single-wavelength laser oscillator (11) supplies a laser beam (LB1) to a fiber optic amplifier (13) through an optical modulator (12). The amplified laser beam is split by splitters (14, 16-1 to 16-m), amplified by optical amplifier units (18-1 to 18-n) and supplied through a fiber bundle (19) to a wavelength converter (20), which in turn converts the split beams into ultraviolet laser radiation (LB5) for use as exposure light. The optical modulator (12) outputs light pulses during the generation of ultraviolet light. The optical modulator (12) also produces laser radiation during the absence of ultraviolet light, but the laser radiation has substantially the same average output and a considerably low peak compared with that during the generation of ultraviolet light.Type: GrantFiled: September 8, 2000Date of Patent: May 31, 2005Assignee: Nikon CorporationInventor: Tomoko Ohtsuki
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Publication number: 20040012844Abstract: The light source unit (16) comprises a single wavelength oscillation light source (160A), a light generating portion (160) which has an optical modulator (160C) converting and emitting light from the light source into a pulse light, a light amplifying portion (161) made up of an optical fiber group that each has a fiber amplifier to amplify the pulse light from the optical modulator, and a light amount controller (16C). The light amount controller (16C) performs a step-by-step light amount control by individually turning on/off the light output of each fiber making up the optical fiber group, and a light amount control of controlling at least either of the frequency or the peak power of the emitted pulse light of the optical modulator.Type: ApplicationFiled: July 15, 2003Publication date: January 22, 2004Applicant: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa, Niichi Atsumi, Masaaki Doi
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Publication number: 20030231663Abstract: An ultraviolet laser apparatus according to the present invention comprises a laser generating portion having a single-wavelength oscillating laser for generating laser light having a single wavelength falling within a wavelength range from an infrared band to a visible band, an optical amplifier having a fiber optical amplifier for amplifying the laser light generated by the laser generating portion, and a wavelength converting portion for wavelength-converting the amplified laser light into ultraviolet light by using a non-linear optical crystal, whereby ultraviolet light having a single wavelength is generated.Type: ApplicationFiled: February 19, 2003Publication date: December 18, 2003Applicant: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Patent number: 6590698Abstract: An ultraviolet laser apparatus has a laser generating single-wavelength light between infrared and visible, a fiber optical amplifier for amplifying the laser light, and a converting portion converting the amplified laser light into single-wavelength ultraviolet light, using a non-linear optical crystal. An exposure apparatus transfers a pattern image of a mask onto a substrate and has light source including a laser apparatus for emitting laser light having a single wavelength, a first fiber optical amplifier for amplifying the laser light, a light dividing device for dividing or branching the amplified laser light into plural lights, and second fiber optical amplifiers for amplifying the plural divided or branched lights, respectively; and a transmission optical system for transmitting the laser light emitted from the light source to the exposure apparatus.Type: GrantFiled: March 30, 2000Date of Patent: July 8, 2003Assignee: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Patent number: 6339634Abstract: A high-pressure krypton gas is supplied to the interior of a vessel from a gas introduction pipe. Light emitted from an optical fiber group formed by bundling together optical fibers constituting the output ends of fiber amplifiers or fiber lasers passes through a lens and exciting laser light introduction window, and is focused on the krypton gas jetting from the tip end of the nozzle. As a result, the krypton gas is excited as a plasma and soft X-rays are generated. The soft X-rays are reflected by a rotating multi-layer coat parabolic mirror and are emitted to the outside as a parallel beam of soft X-rays. Since light from fiber amplifiers is used as exciting light, and since numerous optical fibers are bundled together to form a light source, a large quantity of soft X-rays can easily be obtained.Type: GrantFiled: September 30, 1999Date of Patent: January 15, 2002Assignee: Nikon CorporationInventors: Noriaki Kandaka, Hiroyuki Kondo, Soichi Owa, Tomoko Ohtsuki
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Patent number: 6088379Abstract: An ultraviolet laser apparatus which generates laser light at 193 nm to 213 nm with high temporal and spatial coherence and relatively high power is disclosed. The UV laser apparatus provides a light source for an exposure device for optical lithography and an aberration measurement interferometer that measures lens wave front aberration. The laser apparatus disclosed herein comprises two lasers having laser resonators that are coincident along a portion of their respective optical paths. A nonlinear optical crystal is located along the shared optical path portion for sum frequency generation of the light of the respective lasers.Type: GrantFiled: June 9, 1998Date of Patent: July 11, 2000Assignee: Nikon CorporationInventors: Soichi Owa, Tomoko Ohtsuki
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Patent number: 6078598Abstract: A laser apparatus includes a laser resonator having a first reflective surface and a second reflective surface, the laser resonator further including a laser medium disposed between the first reflective surface and the second reflective surface for processing light reflected from the first and second reflective surfaces to output a laser beam to be resonated, and a resonator loss varying unit disposed between the first reflective surface and the second reflective surface of the laser resonator, the resonator loss varying unit being capable of switching a state thereof between a first state having a resonance frequency substantially coinciding with one of frequencies at which laser oscillation of the laser resonator is possible and a second state having the resonance frequency shifted to the value that is substantially different from any one of the frequencies at which laser oscillation of the laser resonator is possible to vary a loss of the laser resonator.Type: GrantFiled: April 24, 1998Date of Patent: June 20, 2000Assignee: Nikon CorporationInventors: Tomoko Ohtsuki, Soichi Owa
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Patent number: 6049558Abstract: Laser systems, and optical elements for laser systems, are disclosed for providing a pumped laser light with improved output efficiency while having simple construction and simple alignment adjustment. A pump light flux from a diode pumping laser irradiates and thus pumps a solid-state laser crystal. The irradiation by the pump light flux is coaxial with an output laser beam produced by the laser crystal. The pump light flux is conducted by an optical element, preferably frustoconical in shape with an entrance face larger than an exit face, that functions as a light funnel. The entrance face is disposed proximal to the pumping laser 11, and the exit face is disposed proximally to the laser crystal 14. A portion of the pump light flux entering the entrance face passes through the optical element without being reflected by a side surface of the optical element. The remaining pump light flux reflects at least once by the side surface during passage through the optical element.Type: GrantFiled: February 26, 1998Date of Patent: April 11, 2000Assignee: Nikon CorporationInventors: Masaki Harada, Soichi Owa, Tomoko Ohtsuki
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Patent number: 5329505Abstract: A system and method for overwriteable magento-optical recording comprises a medium having a data layer and a reference layer. The medium is heated with a laser pulse of short duration which causes a temperature gradient between the data layer and the reference layer. The temperature of the data layer becomes greater than the Curie temperature of the data layer, but the reference layer remains at a temperature below the Curie temperature of the data layer. The magnetic orientation of the reference layer thus remains unchanged and the data layer will orient itself in the same direction as the reference layer. It is therefore not necessary that the Curie temperature of the reference layer be greater than that of the data layer.Type: GrantFiled: August 18, 1993Date of Patent: July 12, 1994Assignee: IBM CorporationInventor: Tomoko Ohtsuki